Method of making key blanks



June 22, 1 965 g, J, DEMR|cK 3,190,150

' METHOD OF MAKING KEY BLANKS Filed June a 1962 2 Sheets-Sheet 1 Wmh "Wil I CARL J. DEMRICK BY OLSEN mo STEPHENSON A'r'romm June 22, 1965 c. J. DEMRICK 3,190,150

METHOD OF MAKING KEY BLANKS 119d June 8, 1962 ELI- a=a 1m Mm HI INVENTOR. CARL J. DEMRICK OLSEN m STEPHENSON ATTORIIYS United States Patent p 3,190,150 METHOD OF MAIGN G KEY BLANKS Carl J. Demrick, Birmingham, Mich., assignor to Avis Industrial Corporation, Almont, Mich, a corporation of Deiaware Filed June 8, 1962, Ser. No. 201,047

9 Claims. (Cl. 76-110) by appropriate embossing operations. Suitable plating operations may then be performed if desired, and the blank is then in condition to have individual bitting operations performed so that the key will fit a particular lock. In carrying out manufacturing operations of thistype, a substantial amount of sheet metal is converted to i scrap by the initial blanking operation. In normal blanking operations it is found that as much as 25% of the metal stock becomes scrap. The number of key blanks of the character described above that are normally manufactured per day in the United States may run into six or even seven figures, so that it will be realized that a very substantial amount of scrap metal results from the present key blank forming operations. Furthermore, when it is kept in mind that the raw materials comprise the major portion of the costs of a key blank, it will be appreciated that there is a need for animproved method of making key blanks which will eliminate thislargeamount of scrap metal.

It is the principal object .of the present invention to provide an improved method of manufacturing workpieces, such as key blanks and the like, which method utilizes substantially all of the material provided for making the key blanks and which eliminates formation of any scrap material during this operation.

It is another object of the present invention to provide a 'method of making a workpiece of the" foregoing character which includes as' an initial step of the operation a forming step which produces a preliminary blank coritaining metal equal to the weight of the finished key blank andwherein the metal is distributed along the: axisof the preliminary blank generally in proportion to the metal as it exists in the finished key blank. i It is another object of the present invention to provide a method of making a workpiece of the foregoing character wherein the initial step set forth above comprises sintering powdered metal in the general form of the preliminary blank; a

It is another object of the present invention to provide'a method of making a workpiece of the foregoing character wherein the initial step of operation comprises cold heading metal wire stock to the configuration of the preliminary blank.

Still another object of the present invention is to provide a method of forming a workpiece of the foregoing character wherein the preliminary blanks defined in the preceding objects, are cold worked by a pressing operation" which causes the metal of the preliminary blank to flow to the configuration of the key blank.

It is another object of the present invention to provide a method of manufacturing key blanks and the like which is characterized by the low cost of producing the key blanks and in which the finished product is'characteriz'ed by the high quality in details of embossments formed in the key blank and in the accurate configuration thereof. 1 "friiji objects of this invention will appear in,the fol- 3,19%,150 Patented June 2 2,

lowing description and appended claims, reference being had to the accompany drawings forming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views. 7 a In the drawings:

FIGURE 1 is a cylindrical wire blank cut from wire stock for use in carrying out one of the methods embodying thepresent invention for making key blanks;

FIGURE 2 is a side view of the wire blank of FIGURE 1 after a cold heading operation has been performed on the same; I

FIGURE 3 is a front elevation of a preliminary blank formed by a sintering operation of powdered metal;

FIGURE 4 is a front elevation of a key blank formed by the present invention from either of the preliminary blanks shown in FIGURES 2 or 3;

preliminary blanks shown in FIGURES 2 and 3 to the finished blank shown in FIGURES 4 and 5;

FIGURE 7 is a sectional view taken on the line 77 of FIGURE .6; V FIGURE 8 is a fragmentary bottom elevation of the punch illustrated in FIGURE 6; and

FIGURE 9 is a fragmentary top elevation of the die shown in FIGURE 6,. p

Before explaining the present invention in detail, it is to be understood, that the invention is not limited in its application to the details of construction and arrangement of parts illustrated intheaccom'panying drawings, since the inventionis capable of other embodiments and of being practiced or carried out in various ways] Also, it is to be understoodthat the phraseology or terminology employed herein is forjthe purpose of description and not of, limitation. 1 l v Referring now to the drawings," the present invention will be described firstwithrespect to the steps of operation wherein the key blank is made from the wire blank 10 illustrated in FIGURE 1. The blank 14 may be formed from any suitable material that-can be cold formed, and for the purposes of making key blanks, the material may bebrass, bronze, lead, aluminum, copper, and the like. lncutting the wire blank 10 to its proper length, it is important in carrying out the present invention that the length be such that said wire blank 10 has the same weight of metal as will be found in the finished key blank, thus assuring that there will be no waste of metal resulting from scrap. The wire blank 10 is then passed through one or a series of dies where cold forming operations take place to convertthe wire blank 10 tothe shape of the preliminary blank 12 shown in FIGURE 2. In carrying out this latter operation, it is important that the preliminary blank 12 be converted to a shape wherein the different frusto-conical or cylindrical portions14, 15 and 18 thereof conform generally in cross-sectional area to the corresponding cross-sectional areas of the finished key blank 29 shown in FIGURES 4 and 5. Thus, item be seen that the amount of metal in the frusto-conical portion 14 conforms generally to the amount of metal found in the portion 22 of the finished key blank, and it will be noted that the metal in the portion 14 is distributed along the longitudinal axis of the preliminary key blank 12 in generally the same proportion as is found in the portion 22 of the finished key blank 20.' It will also be noted thatthe same condition exists between the cylindrical portions 16 and 24 and the. corresponding portions 18 and 26. e

Following the step of forming the wire blank It} to thesshape of the preliminary blank 12, the'preliminary to form a" green compact.

amount of metal therein as is found in the portions 3 V a a blank 12 is cold worked or, pressed to cause the metal in the preliminary blank 12,.to flow to the finished configuration of the key blank, such as is illustrated in FIG- URES'4 and 5. Y

' If desired,vwhen carrying out the presentinvention," other procedures may be used inmaking the preliminary blank from which no scrap-metal results. Thus, a preliminary blank 28, such as is shown 'in FIGURE 3, may be made by an operation involving sintering powdered metal. In'carrying out thisoperationa metal powdered mixture is fed through alhopper and carefully metered into a die cavity having generally the shape of the blank 28 Where the mixture is'compressed under high pressure I The green compact: is then ejected from the die cavity, placed on a-conveyer of a sinteringfurnace where the powdered particles are bonded 1 having more precise and detailed dimensions and embosstogether. In this sintering operation the compact is heated V to an elevated temperature somewhat belowthe tempera- :1

ture of the major ingredients and ayrelatively. soft and somewhat porous compact is formed. Whenremoved from the furnace the preliminary blank 28 w ill have the.

shape-shown inFIGURE 3, and it is to be noted that the portions 30, 32 and 34 have substantiallyfthe same 24 and 26 ofthe finished key blank 20. It'is also to be noted that the metal in each of the portions 30, 32 and 1 34 is distributed along the longitudinal axis of preliminary blank 28 substantially the same as is found with respect to the distribution of the metal in portions 22, 24 and 26 of the'finished key blank 20. ,While not shown in the,

- drawings, it is to be understood that the preliminary blank 28, because of its porous condition will be somewhat thicker'than the finished key-blank 20. t

The cold working of eitherof the preliminaryblanks 12 or 28 can be performedin the same 'punchand died set,

such asis illustrated in FIGURES 6-9 of the drawings to which {reference -is 'now'madeg As shown intFlG- URE 6, the'punch 36 is mounted for vertical reciprocal -movement on the posts 38 and-the die is held-Sta 'tionary and has acavity for receiving the punch ,36. As

seen in FIGURE 9, the die 40 has a cavity 42 conforming to the outer configuration .of the key blank Ztland the punch 36 has a configuration, shown in FIGURE 8, for

penetrating the cavity 42:1The lower faceiof the punch' 36 is shaped'to define in the upper surface of the blank- 20 the impressions shown'in' FIGURE '4, and the upi in the lower surface of the key blank 20 the impressions shown in 7 FIGURE 5. I shown in FIGURES 4 and 5 can be obtainediby using I :the punch anddie, set 36 40 merely by inserting apre liminary'blank, such as are shown in eitherFIGURESZ V o 3 of the drawings, intothe cavity 42 and thereafter squeezing such preliminary blanks'12 or 28 to cause the metal to flow to the final shape of the-keyblank shown in FIGURES 4 and 5.

, ardly facing wall of the cavity 42 is shaped to define Thus, the -key blank 2 When starting with bar stock and forming a preliminary blank 12, it may be necessary to perform one or'more annealing operations. Thus, if the blanks 12 were made r from brass, it 'normally'would be necessary-to anneal the preliminary blank 12 before performingrthe 'cold forming operation in the punch and die set 36, 40. Also if the preliminary blank 12 were made for example from aluminum, theannealing operation between theytcold heading and cold formingoperations described above would be eliminatedbut a heattreatingsteps would be.

performed to harden the finished key blank following the cold forming operation in thel'punch and die set '36, '40. Such 'heat'treating operations can be eliminatedfcompletely in, such'instances as when the preliminaryblank is made from powdered brass, by sintering operations degnerallyin the planes ofsaid cross sctionaljareaslto, the

scribed above resulting'in the formation of the'preliminary blank 28 In this latter operation, the preliminary blank- 28 will be in a relatively porous state'and will be Y readily susceptible to-a coldworking operation suchas has been described with respect tothe punch and die set,

36, 40, and such cold working will further compress, harden and strengthen the finished key blank.-

,Not only will the present invention result in the complete eliminationof scrap metal in the making of the 1 key blanks, but it will enable key blanksfto'be formed ments; 7 Still further, this method of operation completely eliminates the need for'jsome. of the machine operations which heretofore were" required, such as milling operations to form the grooves 44 and'46, which grooves can be seen in FIGURES 4-and 5 on the upper and lower.

surfaces of the key blank 20,

' If desired, the key blank 20 can be plated or it can be used immediately in therfo'rm from which itlis removed from the punch anddie set 36, 40. The only other opera tion's that must be performed on the key blank 20 to make it usable With-a conventional lockcare the standard bit ting operations that must be per-formed to makea key-fit a'particular lock. a V a J. t V

Having thus described my invention, I claim:

1. The method ofmaking aj key blankwhich has various transverse cross-sectional areas along its longitudinal axis comprising the steps of forming a preliminary blank havingmaterialequal in weight to that of the finished key blank with the; material distributed along the axis-of r the preliminary blank incross-sectional areas thereoiigerb erally in proportion to corresponding tranv'erse cross} sectional areasof the key-blank,tplacing the preliminary blank in the cavity of a'punch and die set which'defines the configuration of the said key blank and which has 'the'longitudi'nal axis of the defined configuration normal -to the path of movementof-thepunch of said set, and 'cold working said preliminary blank'byfexerting, forces on the preliminary blank with the punch of said set in adirection normal to'said longitudinafaxis to flow the V a material of said preliminary blank in the 'planespf-said cross-sectional areas generallyjlaterally with respect to t 'such axis to the final configuration of saidkey blanks;

sintering the green compact,"

; 3. The method of claim '1 wherein the step of forming"; 11 the preliminary 'blank;includes,,cuttinga wire blank which has the same :weight as the desired key blank, and l cold heading the'wire blank to the shape of said pre liminary blank.

'4. The method of making a brass key blank which'has; varioustransverse cross-sectional areas along'its .longitudinalaxis comprising the steps of cutting frombrass. wire stock alwire blank having the weight of said key Z blank, forming a preliminary blank from said wire blank by cold working said wire, blank until the, material is;

distributed along the longitudinal axis thereof generally in i proportion to the cross-sectional areas of said key blank, annealing said preliminary blank, placing the annealed preliminary blankinthe, cavity of a punch and die set which, definesthe config'urationof said key blank and wherein the longitudinal axis of the configuration is Flirt-' ,pendicular'to the path of'movement of the punch of said set and striking the annealed preliminary blank with; the l punch of said set in a direction normal to saidlongitudinal axis to flow the metal of said jannealedpreliminaryblank configuration of said keyvblank, r

2. The method of claim' 1 wherein the step ofform ing thepreliminary' blank includes compacting a.powden mix of said material to a' green compact having the, gen eral shape of said preliminary blank, and thereafter key blank, placing the preliminary blank in the cavity of a punch and die set which defines the configuration of said key blank and wherein the longitudinal axis of the configuration is perpendicular to the path of movement of the punch of said set, engaging the preliminary blank with the punch of said set to flow the metal of said preliminary blank generally laterally in the planes of said cross sectional areas to the configuration of said key blank, and heat treating said key blank to harden the same.

6. The method of making a metal key blank which has various transverse cross-sectional areas along its longitudinal axis comprising the steps of'measuring in weight an amount of powder of said metal corresponding to the weight of said key blank, compressing the measured powder to a green compact'having a shape conforming generally to the shape of said metal key blank, sintering' said green compact, placing the sintered compact in the cavity of a punch and die set which defines the configuration of said metal key blank and in which cavity the longitudinal axis of the configuration is perdendicular to the path of movement of the punch of said set, and cold working the sintered compact with the punch of said set by movement of the punch in such path to flow the metal of the sintered compact generally laterally in the planes of said cross sectional areas to the configuration of said metal key blank.

7. The method of making an elongated metal key, blank which has various transverse cross-sectional areas along its longitudinal axis, comprising the steps of forming a preliminary blank having the same weight of metal as said key blank and having said material distributed along the longitudinal axis of said preliminary blank generally in proportion to said transverse cross-sectional areas of said key blank, and cold Working said preliminary blank in a cavity defining said key blank by striking said preliminary blank in a direction perpendicular to said longitudinal axis to efiect lateral flow of the metal of said preliminary blank in the planes of said cross sectional areas References Cited by the Examiner UNITED STATES PATENTS 774,242 11/04 Gates 76ll0 1,921,654 8/33 Burbank 29-5524 2,301,531 11/42 Falk 76-410 2,757,446 8/56 'Boegehold et a1 29420.5 2,770,818 11/56 Lee et a1. 29-552 GRANVILLE Y. CUSTER, JR., Primary Examiner. 

1. THE METHOD OF MAKING A KEY BLANK WHICH HAS VARIOUS TRANSVERSE CROSS-SECTIONAL AREAS ALONG ITS LONGITUDINAL AXIS COMPRISING THE STEPS OF FORMING A PRELIMINARY BLANK HAVING MATERIAL EQUAL IN WEIGHT TO THAT OF THE FINISHED KEY BLANK WITH THE MATERIAL DISTRIBUTED ALONG THE AXIS OF THE PRELIMINARY BLANK IN CROSS-SECTIONAL AREAS THEREOF GENERALLY IN PROPORTION TO CORRESPONDING TRANSVERSE CROSSSECTIONAL AREAS OF THE KEY BLANK, PLACING THE PRELIMINARY BLANK IN THE CAVITY OF A PUNCH AND DIE SET WHICH DEFINES THE CONFIGURATION OF THE SAID KEY BLANK AND WHICH HAS THE LONGITUDINAL AXIS OF THE DEFINED CONFIGURATION NORMAL TO THE PATH OF MOVEMENT OF THE PUNCH OF SAID SET, AND COLD WORKING SAID PRELIMINARY BLANK BY EXERTING FORCES ON THE PRELIMINARY BLANK WITH THE PUNCH OF SAID SET IN A DIRECTION NORMAL TO SAID LONGITUDINAL AXIS TO FLOW THE MATERIAL OF SAID PRELIMINARY BLANK IN THE PLANES OF SAID CROSS-SECTIONAL AREA GENERALLY LATERALLY WITH RESPECT TO SUCH AXIS TO THE FINAL CONFIGURATION OF SAID KEY BLANK. 